Field of the Invention
Recently, the uses of magnetic tapes have been developed as an audio cassette tape and a home VTR tape in many countries in the world. Therefore, the magnetic tapes have been used in severe conditions. It has been usually blend a rubber component to a resin component as a binder for a magnetic tape because desired flexibility and adhesiveness can not be provided only by a resin component. The rubber component usually has inferior physical characteristics and accordingly, a rubber component having superior physical characteristics should be used. Certain aromatic polyurethanes having relatively superior physical characteristics have been used, however, such aromatic polyurethanes have inferior dispersibility for a magnetic powder and accordingly, the polyurethanes have not been satisfactory in view of electromagnetic characteristics.